Lock washer



Jan. 8, 194 6;

| E. ZERBE LOCK WASHER Filed Oct. 27, 1943 INVENTOR Patented Jan. a, 1946 UNITED STATES PATENT OFFICE 4Claims.

My invention relates to lock washers of various lzes for permanently retaining screws or bolts rith heads having cornered cross sections ornuts raving a cornered cross section, in the position in which they may be set or tightened, or to' permit heir removal or replacement a reasonable-numer of times without injury to any of the assoiated members, regular standard screws or bolts, 1' nuts, of various sizes in common use may be sad without in any way changing their con truction.

Another object of my invention is to produce my lock washers with various means of securin he lock washers against axial rotation with repect to the clamped member. I

Other objects and. advantages will 'be more ully apparent from the following description of he accompanying drawing which forms a part 01 his disclosure, and which illustrate preferred orms of my invention.

I attain these objects by producing my lock washers of thin specially resilient alloy spring teel, scientifically heat treated, and by constructng the lock washers with an annular body porion, having a central screw hole, the outer diamter being divided into six equally, spaced lobes,

ill bent upwardly and outwardly to a predeternined angle, the bottom thus formed'having a iexagon shaped outline to fit the hexagon head If a cap screw, when the screw is in the tightened iosition, the said lobes being directly in the path if the corners of the screw head when the screw s rotated, thus the lobes must be pressed down allow the corners to pass, one of each of, the obes interfering with one of each of the corners n passing, the object being to provide the greatest lumber of pressure points possible simultaneousy. the combined pressure forces being equal to or :reater than the force requiredto unassistedly 'otate the screw, this causes'the least. pressure in the corners of the screw head, thus reducing ahe wear and shear on the comers to a minimum ind providing the greatestlocking and wearing :fllciency possible for boththe washer and the -.crew, various means to prevent rotation of the washer in respect to the clamped member being )rovided and hereinafter described.

My invention is illustrated in the accompanyng drawinggin which:

Fig. 1 is a plan view of a preferred type of my ock washer showing the annular body having )rojections to prevent axial rotation of the lock washer in relation to the clamped member.

Fig. 2 is an elevational view of Fig.- 1 showing '.he lock washer assembled with conventional associated members, the screw head is shown in its position at the moment of making contact with the lock washer.

Fig. 3 is an elevational viewof Fig. 1 showing the lock washer assembled with conventional associated members, the lock washer body is shown pressed solidly fiat lxetween the screw head and the clamped member, the screw head being in the set or. tightened position. v

Fig. 4 is an elevational view of Fig. 1 in section through the lock washer on the line 4-4 showing the lock washer body pressed flat on the clamped member and the upwardly extending resilient lobes on the lock washer are pressed clown toallow the'comers of the screw head to'pass.

Fig. 5 is a plan view of the lock washer similar to that'in Fig. 1 except that a modified type of projection to prevent axial rotation of the lock washer in relation to the clamped member, is shown.

Fig. 6 is an elevational view of Fig. 5 showing the lockwasher assembled with conventional associated members, pressed solidly flat'between the nut and the clamped member, the nut being in the set or tightened position.

Referring to the drawing, the lock washer i Fig. 2 is shown in place on the clamped member 5, which rests on the supportingmember 2i], the body of the screw 3 passes freely through the holes in the washer l and the clamped member 5, the threaded end B of the screw is screwed into the threaded hole 9 in the supporting member 20, until the shoulder s on the screw head I lightly contacts the upper-side of the up-bent I bottom 4 of the washer at themoment when the corners ill on the screw, head 1 make contact l0 are in interference withthe lobes-l |,this force is greater than the-force which'causes the screw 3 to become loo'seand unscrew, rotating-and tightening of the screw 3;Fig. B being continued until the clamped member 5 1s clamped with the required tightness, the screw} is thus securely retained in the set or tightened'positi'on because the corners Hi. Fig. 4, of the screwhead 1 must, be forced to pass the lobes ll before the screw 1 can be freely rotated, the bottom wall 4 Fig. 1 of the lock washer having a hexagon shaped impression l3 "caused by the lobes ll being bent upwardly, around the outer diameter I 4 to the angle l2 Fig. 3 the bends being made on the chord lines l5 Fig. 1 tangent to the circle It, the said circle l8 has a diameter equal to the distance across the flat sides I! Fig. 3 of the screw head I, the outer diameter N Fig. 1 is slightly larger. than the distance across the comers J Fig. 4 of the screw head I, projections I 8 Figs. 1 and 3 hold the lock washer stationary when in contact with shoulder l9 Fig. 3- onthe clamped member when the screw head l'is being rotated. F

30 Fig. 5 shows a, narrow strip Projecting beyond the outer diameter of the lock washer 3i and bent vertically to a point 32 Fig. 6 below the bottom 33 of the lock washer 3| and entering the hole 3| in the clamped member 35 to prevent axial rotation of the lock washer, the nut 36 is number oi! said lobes being equal to the number of corners on the screw head, the said lobes being directly in the path of the comers on the screw head when the screw is rotated, to produce a maximum of resistance to the rotation of the screw with a minimum of force being simultaneously applied to one of each of the comers of the screw head by one 01' each of the said resilient lobes on the washer, two of the said lobes being elongated silient lobes on the washer, one or the said lobes having a lateral extension beyond the annular y P rtion. the said extension being'bent some wardly to extend below the bottom of the lock washer, into rotation resisting relation to one of 1 said associated members.

3. A look washer for use with a hexagon head of a screw used with associated members, one of which has a shouldered portion, the said lock washer being formed from a circular piece of sheet metal without slits or penetrating teeth,,

with a central screw hole through the flat bottom and surrounded by six equally spaced resilient lobes, eachlobe being;bent upwardlyandoutwardly on a line tangent to acircle having a diameter equal to the distance across the flats of the said screw head, the said lobes being directly in the path of the cornerson' the screw headwhen the screw is rotated, to produce a .maximum of intermittent resistance to the rotation of the screw with a minimum of force siand bent over at the tops to extend outwardly on a plane parallel with the bottom of the'washer .to form stops to prevent axial rotation of the lock washer, when said stopsabut a shouldered portion on one of the said associated members.

2. A look washer for use with a hexagon head cap screw and associated members, formed from resilient sheet metal, having an annular body portion with a central screw hole, with equally spaced resilient exterior lobes extending upwardly and outwardly at a predetermined angle, the number of said lobes being equal to thenumber of corners on the screw head, the said lobes being directly in the path of the corners on the screw head when the screw is rotated, to produce a maximum of resistance to the rotation of the screw with a minimum of force being simultaneously applied to one of each of the corners of multaneously applied to one of each of the corners of the screw head by one of each of the said resilient lobes on the washer, the body portion of the said lock washer beingtightly clamped to the clamped member by the screw head, when the screw is in the tightened position, two of the said lobes being elongated and bent over at the tops to extend outwardly on a plane parallel with the bottom of the washer, to form stops to prevent axial rotation of the lock washer, when the said stops abut said shouldered portionof one of the said associated members. T.

4. A look washer for use with the hexagon head.

of a screw used with associated members, the said lock washer being formed from a circular piece of sheet metal without slits or penetrating teeth, with a central screw hole through the flat bottom and surrounded by six equally spaced resilient lobes, each lobe being bent upwardly and outwardly on a line tangent to a circle having a diameter equal to the distance across the flats of .the said screw head, the said lobes being directly in the path of the corners on the screw head when the screw is rotated, to produce the maximum of intermittent resistance to the rotation of the screw with a minimum of force simultaneously applied to one of each of the comers of the screw head by one of each ;of the said resilient lobes on the washer, the body portion of. the said lock washer being tightlyclamped to the clamped member by the screw head, when the screw is in the tightened position, one of the said lobes having a lateral extension beyond the annular body portion, the said extension being bent downward- 1y to extend below the bottom of the lock washer, into rotation resisting relation to one of the said associated members.

. LE, WIS E. ZERBE. 

